X-Original-To: pgsql-performance-postgresql.org@postgresql.org Received: from localhost (wm.hub.org [200.46.204.128]) by postgresql.org (Postfix) with ESMTP id 030149FB1DA for ; Tue, 15 Aug 2006 16:36:44 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.128]) (amavisd-new, port 10024) with ESMTP id 37419-01 for ; Tue, 15 Aug 2006 19:36:31 +0000 (UTC) X-Greylist: delayed 00:26:33.189228 by SQLgrey- Received: from svr4.postgresql.org (svr4.postgresql.org [66.98.251.159]) by postgresql.org (Postfix) with ESMTP id 6B7159FB235 for ; Tue, 15 Aug 2006 16:36:31 -0300 (ADT) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.3 Received: from home.wiles.org (frank.wiles.org [24.124.39.75]) by svr4.postgresql.org (Postfix) with ESMTP id 126345AF88B for ; Tue, 15 Aug 2006 19:09:55 +0000 (GMT) Received: from localhost.localdomain (frank.wiles.org [24.124.39.75]) by home.wiles.org (8.13.6/8.13.6) with SMTP id k7FJ9rAd012551; Tue, 15 Aug 2006 14:09:53 -0500 Date: Tue, 15 Aug 2006 14:08:06 -0500 From: Frank Wiles To: "Carl Youngblood" Cc: pgsql-performance@postgresql.org Subject: Re: Beginner optimization questions, esp. regarding Message-Id: <20060815140806.8c73ef5f.frank@wiles.org> In-Reply-To: References: <44DAFB2B.4070307@archonet.com> <20060815150529.GO27928@pervasive.com> X-Mailer: Sylpheed version 2.2.6 (GTK+ 2.8.20; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=0.135 tagged_above=0 required=5 tests=FORGED_RCVD_HELO X-Spam-Level: X-Archive-Number: 200608/242 X-Sequence-Number: 20427 On Tue, 15 Aug 2006 12:47:54 -0600 "Carl Youngblood" wrote: > I tried setting it to 2GB and postgres wouldn't start. Didn't > investigate in much greater detail as to why it wouldn't start, but > after switching it back to 1GB it started fine. > > On 8/15/06, Jim C. Nasby wrote: > > See the recent thread about how old rules of thumb for > > shared_buffers are now completely bunk. With 4G of memory, setting > > shared_buffers to 2G could easily be reasonable. The OP really > > needs to test several different values with their actual workload > > and see what works best. Sounds like you need to increase your kernel's maximum amount of shared memory. This is typically why an increase in shared_buffers causes PostgreSQL not to start. Check out this page in the docs for more information: http://www.postgresql.org/docs/8.1/static/kernel-resources.html --------------------------------- Frank Wiles http://www.wiles.org ---------------------------------